Arrangement for measuring the temperature of an extrusion during the manufacture thereof



Nov. 3, 1964 G. MAI 3,155,237

ARRANGEMENT FOR MEASURING THE TEMPERATURE OF AN USION DUR G THEMANUFACTURE THEREOF 2 She E Original Filed Dec. 1959 ets-Sheet 1 WgmNov. 3, 1964 G. MAI 3,155,237

ARRANGEMENT FOR MEASURING THE TEMPERATURE OF AN EXTRUSION DURING THEMANUFACTURE THEREOF Original Filed Dec. 28, 1959 2 Sheets-Sheet 2 F/GJIN V EN TOR.

United States Patent ARRANGEMENT F03 MEASURTNG TEE TEMPER- ATURE 6F ANEXTRUSHGN BURTNG THE MAN- UFACTURE Gerhard Mai, Meinerzhagen,Westphaiia, Germany, assignor to Otto Fuchs Kommandit-Geseilschaft,Meinerzhagen, Westphaiia, Germany Continuation of appiication Ser. No.862,217, Dec 23,

1959. This appiication Nov. 12, 196?), Ser. No. 325,290 Claims priority,application Germany, Dec. 27, 1958, F 27,377; Nov. 23, M59, F 29,%3 8laims. (Cl. 2fl716) The present invention relates to extrusions and inparticular to the manufacture thereof.

The present application is a continuation of my copending applicationSerial No. 862,217, filed December 28, 1959, entitled Arrangement forMeasuring the Temperature of an Extrusion, and now abandoned.

It is known that in order to obtain high quality extrusions thetemperature of the extrusion material must be closely regulated duringthe extrusion of this material. Thus, it is desirable to maintain thetemperature of the extrusion material during the extrusion thereof veryclose to that temperature at which the extrusion material, or in thecase of an alloy the component thereof with the lowest melting point,will start to melt. Thus, itis desirable in the case of an alloy, forexample, to maintain the extrusion temperature within 10-30 C. belowthat temperature at which the component of the alloy of lowest meltingpoint will start to melt.

Of course, once the temperature is accurately measured it is not toodifficult to maintain the extrusion material at the desired temperaturesimply by controlling the rate of extrusion thereof.

However, considerable difiiculty is encountered in accurately measuringthe temperature of the extrusion material during the extruding thereof.For example, it has been proposed to place in engagement with theextrusion material during the extrusion thereof a thermocouple structurewhich will give a temperature indication, but this engagement is broughtabout by placing rolls or a spring element or the like in engagementwith the exterior surface of the extrusion, and since a certain pressureis required to provide the desired accurate temperature reading, it isalmost impossible to take a measurement in this way without damaging thesurface of the extrusion undesirably. Furthermore, the known measuringdevices are rather bulky and because of their own mass do not giveaccurate temperature readings. Moreover, it has proved in practice thatin taking the measurements of the temperature what is actually arrivedat is a more or less average temperature of the extrusion materialinstead of the critical highest temperature thereof.

It is accordingly one of the objects of the present invention toovercome the above drawbacks by providing an apparatus which will givean accurate indication of the highest temperature of the extrusionmaterial during the extruding thereof.

Another object of the present invention is to provide an apparatus whichis extremely simple while at the same time operating very reliably toproduce the desired results.

With the above objects in view the invention includes in an apparatusfor measuring the temperature of an extrusion during the manufacturethereof, an extrusion means for extruding an electrically conductivematerial. The first thermocouple element is located at one end closelyadjacent to the extrusion material at a part thereof which passesthrough an extruding die of the extrusion means, and this thermocoupleelement has a free end distant from the extrusion means. An electricalconductor is directly in engagement with the extrusion material and alsohas a free end distant from the extrusion means,

3,155,237 Patented Nov. 3, 1964 and a means is connected electricallywith the free end of the conductor and the free end of the firstthermocouple element for indicating the temperature of the extrusionmaterial at the region where it is located next to the firstthermocouple element. It will be seen that with this arrangement it isthe extrusion material itself which forms the second thermocoupleelement.

The novel features which are considered as characteristic for theinvention are set forth in particular in the appended ctaims. Theinvention itself, however, both as to its construction and its method ofoperation, together with additional objects and advantages thereof, willbe best understood from the following description of specificembodiments when read in connection with the accompanying drawings, inwhich:

FIG. 1 is a fragmentary, diagrammatic, longitudinal section of anextrusion material shown being extruded, FIG. 1 illustrating how onethermocouple element is incorporated into the assembly;

FIG. 2 is a perspective illustration of the extruding die and theextrusion issuing therefrom, FIG. 2 showing in a partly diagrammaticmanner the manner in which the thermocouple elements are electricallyconnected together;

FIG. 3 is a longitudinal, fragmentary, diagrammatic section illustratingthe extrusion means together with the extrusion material and thestructure for indicating the temperature thereof, the embodiment of FIG.3 differing from that of FIG, 2;

FIG. 4 is a diagrammatic longitudinal fragmentary section of anotherembodiment of an arrangement according to the invention for indicatingthe temperature of the extrusion material during the extrusion thereof;and

FIG. 5 is still another embodiment of a structure for indicating thetemperature of the extrusion material during the extrusion thereof.

Referring now to the drawings and to FIG. 2 in particular, it will beseen that a die 21 of an extrusion means is shown in FIG. 1 with theextrusion 23 issuing forwardly from the extrusion die 21. This extrusionmaterial 23 may be an aluminum alloy, for example. In order to determinethe highest temperature of the material 23 during the extrusion thereofit is necessary to arrange the temperature measuring structure so thatit will detect the temperature of the extrusion 23 at the point whereits temperature is highest, and then, as was pointed out above, theextrusion will be carried out in such a way that the extrusion materialis maintained very close to the maximum possible temperature. Where thecross section of the extrusion varies, as indicated in FIG. 2, thehighest temperature will occur at that part of the extrusion where itsthiclciess is at a minimum and where the extrusion just issues from thedie 21. In accordance with the present invention one element 24 of athermocouple is fixed by a fastening means in the form of a screw 29 tothe die 21 closely adjacent to the die orifice portion at which the partof the extrusion 23 of smallest thickness issues. In the illustratedexample the thermocouple element 24 is in the form of a copper wirewhose one end is fixed by the screw 29 to the die very closely adjacentto the part of the die orifice through which the extrusion portionofysmallest thickness flows, and it will be seen that the thermocoupleelement 24 has a free end distant from the extrusion means whichincludes the die 21.

An electrical conductor 25 is connected electrically with theelectrically conductive extrusion material 23 which in the illustratedexample is an aluminum alloy, as pointed out above. In order to connectthe conductor 25 electrically with the extrusion 23 a gripping tongs isused, and as shown in FIG. 2 the tongs 22 grip the one end of 03 s) theconductor 25 together with the extrusion 23 at its leading end so thatthrough the tongs 22 the conductor 25 is connected electrically with theextrusion 23. It will be noted that the conductor 25 also has a free enddistant from the extrusion 23. A temperature indicating means 39 isconnected with the free ends of the thermocouple element 24 and theconductor 25, and this means 36 may be in the form of a galvanometer,for example, whose pointer can directly indicate temperature.

It will be seen that with this arrangement the extrusion material 23itself forms the second element of the thermocouple.

As is well known, a thermocouple is composed of a pair of conductorsjoined at their ends and where there is a temperature difference betweenthe two junctions of the conductors of diiferent materials anelectromotive force will be generated, and this is what is measured bythe galvanometer 39 which directly indicated the temperature. Of course,in the example illustrated in PEG. 2 there is an extremely small amountof the material of the die 21 itself located between the thermocoupleelement 24 and the extrusion material, so that actually what is measuredin the embodiment of FIG. 2 is the temperature of the die 21 at theextremely small portion thereof which is located between the screw 29and the extrusion material 23. However, inasmuch as the ter iperature ofthis extremely small portion of the die 21 is in fact the same as thetemperature of the extrusion 23 which it directly contacts, it is clearthat the means 39 will provide an accurate indication of the temperatureof the extrusion material precisely at the point where this temperatureis highest.

It should be noted that the thermocouple illustrated in FIG. 2 departsslightly from a classic thermocouple in that the element 2 4 is notdirectly in engagement with the other thermocouple element 23. However,it is known, for example, that when a pair of thermocouple elements areimmersed in a bath of molten metal in order to determine the temperaturethereof, the temperature at the junction of the two thermocoupleelements is not actually measured in this instance. What is actuallymeasured is the temperature of the molten metal bath at a point closelyadjacent to the surface of the bath, since the electrical currentobviously follows the line of least resistance and therefore the circuitis between the pair of thermocouple elements at the portion thereofclosely adjacent to the surface of the molten metal bath. Thus, in thecase of FIG. 2 the measurement is of the temperature of the material ofthe die 21 between the screw 2h and the edge of the extrusion 23 wherethe latter is of smallest thickness. It is known, for example, tomeasure the temperature of the surface of the metal block by using apair of thermocouple elements which are in fact sharply pointed metalmembers spaced slightly from each other and piercing the surface of theblock to obtain a measurement thereof, so that in a device of thislatter type also there is no direct engagement between the ends of thethermocouple elements. I

Inasmuch as the thermocouple operates on the principle of generating theelectromotive force as a result of the difference between thetemperatures at the two junctions of the pair of thermocouple elements,it is clear that an accurate reading of the desired temperature with theembodiment of FIG. 2 requires that the temperature at the galvanometer30 be constant. It is for this reason that the conductor 25 is used. Ifthe galvanometer fill were located, for example, at the leading end ofthe extrusion 23 connected electrically with the latter, then thetemperature at the junction distant from the screw 29 would varyconsiderably because of the continuous cooling of the leading end of theextrusion, and it would be impossible to obtain an accurate reading.However, by using conductor 25 it is possible to maintain the functionat the galvanometer 30 at a substantially constant temperature and thusan accurate reading would be obtained. The

material of the conductor 25 may be the same as the mate-. rial of theextrusion 23. However, if desired the material of the conductor 25 maybe different from that of the extrusion 23 but in this event it souldbehave the same as the material of the extrusion 23. Thus, it is known,for example, that where a thermocouple includes a plat inum element anda platinum-rhodium element, a copper alloy wire corresponding to theconductor 25 may be used since it has thermoelectric properties similarto that of the thermocouple elements. In the same way, any wire 25 whosematerial has the same thermoelectric properties as the material of theextrusion 23 may be used.

In FIG. 1 there is shown an embodiment which differs from that of FIG. 2only in that with the embodiment of FIG. 1 there is in fact directcontact between the pair of thermocouple elements. Thus, referring toFIG. 1 it will be seen that the extrusion material 2 moves throu theextrusion die 1 to form the extrusion 3. The die 1 is formed with a boreill receiving a tube ll, and the thermocouple element 12, whichcorresponds to the thermocouple element 2 2- of FIG. 2, passes throughand is insulated from the tube 11. The thermocouple element 12terminates extremely close to the inner end of the bore 10 very close tothe inner surface of the die 1 along which the extrusion material flows,and with this arrangement a part of the extrusion material will moveinto the bore 10 and will directly engage the thermocouple element 12 soas to enable the desired temperature to be indicated in the same way asdescribed below in connection with FIG. 2. Thus, the thermocoupleelement 12 at its end distant from the extrusion means 1 will beconnected with a means 3% or the like for indicating the temperature,and a conductor similar to the conductor 25 of FIG. 2 will be connectedthrough a tongs 22 or the like to the extrusion 3 so as to complete thecircuit, this extrusion 3 itself forming the second thermocoupleelement. Of course, where the extrusion 3 has an irregular crosssection, the inner end of the bore it) is located at a part of the diewhich will produce the smallest cross sectional thickness of theextrusion 3.

Of course, with an arrangement as shown in FIGS. 1 and 2, bearing inmind that the reading at the instrument 36 will be influenced by theresistance of the circuit itself, a false reading may be obtainedbecause the extrusion 23 is constantly increasing in length and thusintroducing additional resistance constantly into the circuit. However,all that is required is to use at the instrument 3!) a rotor of highresistance in relation to the total resistance of the circuit itself, sothat any possible increase in the resistance resulting from theincreased length of the extrusion 23 will be so small in comparison tothe resistance of the rotor of the instrument 30 that the increasingresistance produced by the increasing length of the extrusion 23 cansimply be ignored.

Instead of a tongs 22, it is possible to provide a carriage which willroll along the base of the machine or the floor which carries theextrusion means, and such a carriage may be connected with the leadingend of the extrusion 23 and may serve to maintain the flexible elongatedconductor 25 electrically connected with the extrusion 23.

The advantage of the structure of the invention can be readilyappreciated with reference to the point 13 illustrated in FIG. 1. If athermo-element of a thermocouple is placed at the point 13, as is oftendone in practice, then of course there will be a more or lesssubstantial distance between the point at which the temperaturemeasurement is made and the discharge end of the die. Thus, it will beimpossible to obtain at the point 13 the maximum temperature of thematerial in the die even if thepoint 13 is taken at the part of theextrusion which has the smallest thickness. It is the part of thematerial of smallest thickness at the discharge of the die itself whichis at the highest temperature and this is the critical temperature whichshould be determined, and by taking a reading at the point 13 there hasbeen such a drop of temperature from the die to the point 13 that it isimpossible to determine what the actual temperature of the extrusionmaterial is at the critical point where it issues from the die. Ofcourse, it is also possible to measure the temperature by utilizing theradiation from the extrusion at the region 13 thereof, but tests haveshown that when using this temperature measuring method also there isvery little accuracy. It is almost im possible to obtain a preciserelationship between the temperature obtained from radiations at theregion 13 and the maximum temperature of the extrusion material in thedie itself. Inasmuch as it is known that the radiation factor of steelis approximately 0.8 and that of aluminum approximately 0.3, then duringthe extrusion of aluminum or aluminum alloy, for example, the radiationof the aluminum or aluminum alloy extrusion material is super-imposed onradiations from the extrusion die and even from the billet receiver ofthe extrusion apparatus, so that false readings are obtained. Underthese circumstances, a measurement of radiations from the extrusion donot give an accurate indication of temperature in the dieand of coursethe further away the measurement is made from the die the greater arethe possible errors.

Inasmuch as the connection of the flexible conductor 25 to the leadingend of the extrusion 23 creates some ditficulties, arrangements such asthose illustrated respectively in FIGS. 3-5 may be used to obviate thisdifiiculty.

Thus, referring to FIG. 3 it will be seen that an extrusion apparatus ormeans which includes the die 31, the billet receiver 36, and the ram 37is provided. The extrusion material includes the billet 32 which isorigi nally placed within the billet receiver 36, the ram 37 advancingto the left, as viewed in FIG. 3, so as to cause the extrusion material32 to flow through the die 31 and form the extrusion 33. The firstthermocouple element 34 is shown in FIG. 3 diagrammatically connected tothe apparatus at 35. At the region 35 the connection may be either thatshown in FIG 1 for the thermocouple element 12 or that shown in FIG. 2for the thermocouple element 24. The instrument 4% may be the same asthe instrument 30, and in accordance with the embodiment of FIG. 3 theconductor 38 extends from the instrument 46 through a bore 39 with thefree end of the conductor 38 located directly in the billet receiver 36so as to be directly engaged by the extrusion material 32, and thus withthis embodiment the extrusion material 32, 33 will also form the secondthermocouple element which cooperates with the thermocouple element 34to indicate at the instrument 40 the temperature of the material 32, 33in the die 31.

With the embodiment of FIG. 4 the extrusion means includes the die 41,the billet receiver 46 and the ram 47. The billet 42 within the receiver46 is extruded through the die 41 to form the extrusion 43 byadvancingof the ram 47 to the left, as viewed in FIG. 4. The instrument 5!) ofFIG. 4 corresponds to the instrument 30 of FIG. 2 and is connected toone end of the thermocouple element 44 whose opposite end is connectedat 45 to the extrusion means in such a way that this thermocoupleelement 44 is connected either in the same way as the thermocoupleelement 24 or in the same way as the thermocouple element 12. With theembodiment of FIG. 4 it is the wall of the receiver 46 which is formedwith a bore 49, and the conductor 48 extends from the instrument 54?through the bore 49 into the interior of the receiver 46 so as to be indirect engagement with the material 42 within the receiver 46 and thuscomplete the circuit so as to provide at the instrument St the desiredtemperature indication.

In the embodiment of the invention which is illustrated in FIG. 5 theextrusion means again includes the die 51, the billet-receiver 56 andthe ram 57. The extrusion billet S2 is placed within the receiver 56 andis extruded through the die 51 while the ram 5'7 advances to the left,as viewed in FIG. 5, thus producing the extrusion 53. The firstthermocouple element 54 is connected at its outer free end to theinstrument 60 which corresponds to the instrument 30, and at 55 thethermocouple element 54 is assembled with the rest of the apparatuseither in the manner illustrated for the thermocouple element 24 of FIG.2 or in the manner illustrated for the thermocouple element 12 ofFIG. 1. With the embodiment of FIG. '5 it is the ram 57 itself which isformed with a bore 59 part of which extends am'ally or parallel to theaxis of the ram 57 and part of which extends radially thereof to theexterior surface of the ram 57, the conductor 58 passing through thisbore 59 and terminating at the left end face of the ram 57 so as to bein direct engagement with the extrusion material 52, the outer free endof the conductor 58 being connected with the instrument so, so that inthis way with embodiment of FIG. 5 there will also be provided a circuitin which the extrusion material 52, 53 itself forms the secondthermocouple element.

The insulating tube 11 of FIG. 1 is in the form of a tube of anysuitable material which provides electrical insulation.

It will be understood that each of the elements described above, or twoor more together, may also find a useful application in other types ofextrusion apparatus diifering from the types described above.

While the invention has been illustrated and described as embodied inthe temperature measurement arrangement for extrusions, it is notintended to be limited to the details shown, since various modificationsand structural changes may be made without departing in any way from thespirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledgereadily adapt it for various applications without omitting featuresthat, from the standpoint of the prior art, fairly constitute essentialcharacteristics of the generic or specific aspects of this inventionand, therefore, such adaptations should and are intended to becomprehended within the meaning and range of equivalents of thefollowing claims.

What is claimed as new and desired to be secured by Letters Patent is:

1. An arrangement for determining the temperature of an extrusion duringthe manufacturer thereof, comprising, in combination, extrusion meansfor extruding a given electrically conductive extrusion material, saidextrusion means including an extrusion die having an outlet end fromwhich the extruded material issues; a first thermocouple elernent,having thermoelectric properties different from that of the extrusionmaterial, supported by said extrusion means closely adjacent to theextrusion material adjacent said outlet end of said die at apredetermined region of the latter and said first thermocouple elementextending away from said extrusion means; an electrical conductorengaging and having substantially the same thermoelectric properties asthe extrusion material; and means connected electrically with saidconductor and said first thermocouple element for indicating thetemperature of a point on the extrusion material at the region wheresaid first thermocouple element terminates adjacent to said extrusionmaterial, whereby the extrusion material itself forms the secondthermocouple element.

2. Apparatus for measuring the temperature of an extrusion during themanufacture thereof, comprising, in combination, extrusion means forextruding an electrically conductive extrusion material, said extrusionmeans including a die having an irregular orifice through which theextrusion material flows to form an extrusion of nonuniform crosssection and said orifice having an outlet end from which the extrudedmaterial issues; a first thermocouple element, having thermoelectricpropertiessubstantially the same thermoelectric properties as theextrusion material and also having a free end distant from saidextrusion means; and means interconnecting the free ends of said firstthermocouple element and said conductor for indicating the temperatureof a point on the extrusion material at that portion thereof which isadjacent to the end of the first thermocouple element carried by saiddie, whereby the extrusion material itself I forms the secondthermocouple element.

3. Apparatus for measuring the temperature of an extrusion during themanufacture thereof, comprising, in combination, extrusion means forextruding an electrically conductive extrusion material, said extrusionmeans including a die through which the extrusion material flows to forman extrusion of a given cross sectional configuration, said die havingan outlet end from which the extruded material issues and saiddiebeingformed with a bore passing therethrough from the exteriorthereof closely adjacent to said outlet end at a'region through whichthe extrusion material flows; a tube located in said bore; an elongatedfirst thermocouple element having thermoelectric properties difierentfrom that ofthe extrusion material, extending into and insulated fromsaid tube and terminating closely adjacent to that end of the bore ofsaid die which is next to the extrusion material, whereby a part of theextrusion material will flow into said latter end of said bore tocontact the first thermocouple element, the latter having a free endlocated distant from said extrusion means; a conductorconnected-electrically with and having substantially the samethermoelectric properties as the extrusion material and also having afree end distant from said extrusion means; and means connected with thefree ends of said first thermocouple element and said conductor forindicating the temperature of the extrusion material at the portionthereof which engages the first thermocouple element, whereby theextrusion material itself forms the second thermocouple element.

4. Apparatus for measuring the temperature of an extrusion during themanufacture thereof, comprising, in combination, extrusion meansincluding an extruding die having an outlet end from which the extrudedmaterial issues, said extrusion means extruding an electricallyconductive extrusion material; anelongated first thermocouple elementhaving thermoelectric-properties"diflerent from that of the extrusionmaterial and having one end at a location next to said die at apredetermined point thereof adjacent said outlet end, said firstthermocouple element having an opposite end distant from said extrusionmeans; fastening means fastening said one end of said first thermocoupleelement to said die at saidllocation closelytadjacent to the extrusionmaterial'which flows through the die; an electrical conductorconnected'with and having substantially the same thermoelectricproperties as the extrusion material and having a free end distant fromsaid extrusion means; and means connected electrically with saidfree endof said conductor and said opposite end of said first thermocoupleelement for indicating the temerature of the die at the point thereof towhich the first thermocouple element is fastened, said point of middlebeing at the same temperature as the extrusion material, whereby theextrusion material'itself forms the second thermocouple element. v

5. Apparatus for measuring the temperatureof an extrusion during themanufacture thereof, comprising, in

combination, extrusion means for extruding an electrically conductiveextrusion material, said extrusion means including an extrusion diehaving an outlet end from which the extruded material issues; a firstthermocouple element, having thermoelectric properties different fromthat of the extrusion material, supported in part by said extrusionmeans and located directly next to the'extrusion material adjacent saidoutlet end of said die at a predetermined region thereof; an electricalconductor having substantially the same thermoelectric properties as theextrusion material and having a free end located adjacent a free end ofsaid first thermocouple element which is distant from said extrusionmeans; means for electrically connecting a part of said conductordistant from said free end thereof with the extrusion adjacent theleading end thereof as the extrusion is extruded and advances rom theextrusion means; and means connected to the tree'end of saidconductorand the end of said first thermocouple element distant from saidextrusion means forindicating the temperature of the extrusion materialat a point thereof located next to said first thermocouple element,whereby the extrusion material itself forms the second thermocoupleelement.

6. Apparatus for measuring the temperature of an extrusion duringthemanufacture thereof, comprising, in combination, extrusion means forextruding anelectrically conductive material, said extrusion meansincluding a die through which the extrusion materialifiows and said dieI having an outlet end from which the extruded material issues; a firstthermocouple element having thermoelectric properties different fromthat of the extrusion material and having one end located closelyadjacent to a predetermined point on the extrusion material at said dieadjacent the outlet end thereof and having an opposite end distant fromsaid extrusion means; an electrical conductor having substantially thesame thermoelectric properties asthe extrusion material and having aportionpassing through said die and engaging the extrusion material at apart thereof next to said die, said electrical conductor having a freeend distant from said extrusion means; and means connected with saidfree end of said electrical conductor and with said opposite end of saidfirst thermocouple element for indicating the temperature of saidpredetermined point on the extrusion material closely adjacent to saidone end of said first thermocouple element, whereby the extrusionmaterial itself forms the second thermocouple element.

7. Apparatus for measuring the temperature of an extrusion during themanufacture thereof, comprising, in combination, extrusion means forextruding an electrically conductive extrusion material, said extrusionmeans including a die and a billet receiver connected with said die forfeeding to the latter the extrusion material originally located in saidreceiver in the form of a billet, said die having an outlet end fromwhich the extruded material issues; a first thermocouple element havingthermoelectric properties different from that of the extrusion materialand having one end located, closely adjacent to a predetermined point onthe extrusion material at said outlet end of said die and having a freeend distant from said extrusion means; an electrical conductor havingsubstantially the same thermoelectric properties as the extrusionmaterial and passing through a Wall of said billet receiver and engagingthe extrusion material in said receiver, said conductor having a freeend distant from said extrusion means; and means connected with saidfree end of said conductor and said free end of said first thermocoupleelement for indicating the temperature of the extrusion material at thepredetermined point thereof adjacent to said one end of said first; Y

thermocouple element, whereby the extrusion material itself forms thesecond thermocouple element. H

8., Apparatus for measuring the temperature of an extrusion during themanufacture thereof, comprising, in combination, extrusion means forextruding an electrically conductive extrusion material, said extrusionmeans including a die, a billet receiver Which contains the extrusionmaterial originally in the form of a billet, and a ram for advancing theextrusion material out of the receiver and through the die, said diehaving an outlet end through which the extruded material issues; a firstthermocouple element having thermoelectric properties different fromthat of the extrusion material and having one end located closelyadjacent to a predetermined point on the extrusion material at saidoutlet end of said die and having a free end located distant from saidextrusion means; an elongated electrical conductor having substantiallythe same thermoelectric properties as the extrusion material and passingthrough a part of said ram and engaging the extrusion material, saidconductor also having a free end distant from said extrusion means; andmeans connected 10 electrically with the free ends of said conductor andfirst thermocouple element for indicating the temperature of theextrusion material at the predetermined point thereof next to said firstthermocouple element, whereby the extrusion material itself forms thesecond thermocouple element.

References Cited in the file of this patent UNITED STATES PATENTS1,379,909 Gilbert May 31, 1921 1,988,849 McBurney Jan. 22, 19352,102,955 Hulme Dec. 21, 1937 2,105,083 Kagi et a1. Jan. 11, 19382,161,570 Harris June 6, 1939 2,658,687 Southworth N0v.10, 1953

1. AN ARRANGEMENT FOR DETERMINING THE TEMPERATURE OF AN EXTRUSION DURINGTHE MANUFACTURER THEREOF, COMPRISING, IN COMBINATION, EXTRUSION MEANSFOR EXTRUDING A GIVEN ELECTRICALLY CONDUCTIVE EXTRUSION MATERIAL, SAIDEXTRUSION MEANS INCLUDING AN EXTRUSION DIE HAVING AN OUTLET END FROMWHICH THE EXTRUDED MATERIAL ISSUES; A FIRST THERMOCOUPLE ELEMENT, HAVINGTHERMOELECTRIC PROPERTIES DIFFERENT FROM THAT OF THE EXTRUSION MATERIAL,SUPPORTED BY SAID EXTRUSION MEANS CLOSELY ADJACENT TO THE EXTRUSIONMATERIAL ADJACENT SAID OUTLET END OF SAID DIE AT A PREDETERMINED REGIONOF THE LATTER AND SAID FIRST THERMOCOUPLE ELEMENT EXTENDING AWAY FROMSAID EXTRUSION MEANS; AN ELECTRICAL CONDUCTOR ENGAGING AND HAVINGSUBSTANTIALLY THE SAME THERMOELECTRIC PROPERTIES AS THE EXTRUSIONMATERIAL; AND MEANS CONNECTED ELECTRICALLY WITH SAID CONDUCTOR AND SAIDFIRST THERMOCOUPLE ELEMENT FOR INDICATING THE TEMPERATURE OF A POINT ONTHE EXTRUSION MATERIAL AT THE REGION WHERE SAID FIRST THERMOCOUPLEELEMENT TERMINATES ADJACENT TO SAID EXTRUSION MATERIAL, WHEREBY THEEXTRUSION MATERIAL ITSELF FORMS THE SECOND THERMOCOUPLE ELEMENT.